The applicant of the present application has proposed an actuator which includes a drive means such as a motor or the like and a movable member that is displaceable by the drive means, the drive means and the movable member being accommodated in a recess in a structural member which comprises a substantially elongate columnar body, and also proposed a structural assembly (Japanese laid-open patent publications Nos. 5-69352, 5-180295, 5-180296, and 5-180297). In the proposal, there has been used a term "structural member" which represents a concept including both an outer frame of an actuator and a columnar elongate member. The term will be used below as meaning the same concept.
According to the technical ideas disclosed in the above publications, a plurality of structural members which are of substantially the same shape may be assembled by joint mechanisms into a structural assembly that has a desired function.
One example of the joint mechanisms disclosed in the above publications is a locking member 2 for joining structural members as shown in FIG. 1 of the accompanying drawings. As shown in FIG. 1, one end of the locking member 2 is inserted into a hole 6 defined longitudinally in a structural member 4, and a head 8 on the other end of the locking member 2 is loosely fitted in a slot 10 defined in another structural member 4a. Then, a screw 14 is threaded through a plate 12 transversely into the structural member 4 until a tip end 16 of the screw 14 is held against a slanting surface 18 of a notch defined substantially centrally in the locking member 2. The tip end 16 is of such a tapered configuration that when the screw 14 is threaded in, the tip end 16 presses the slanting surface 18, displacing the locking member 2 in the direction indicated by the arrow A in FIG. 3 of the accompanying drawings. When the locking member 2 is displaced in the direction indicated by the arrow A, the head 8 of the locking member 2 pulls an inner wall surface of the other structural member 4a also in the direction indicated by the arrow A. As a result, the structural members 4, 4a are fixedly joined to each other substantially perpendicularly to each other as shown in FIGS. 2 and 3 of the accompanying drawings. The locking member 2 is normally biased in the direction indicated by the arrow B under resilient forces from a spring 19.
The present invention has been made in relation to the above proposals. It is an object of the present invention to provide an improved joint mechanism for joining structural members while keeping passages defined in the structural members in communication with each other.
Another object of the present invention is to provide a joint mechanism which joins structural members substantially in line or perpendicularly through slots defined longitudinally in the structural members, so that a structural assembly can simply be constructed of the joined structural members.
Still another object of the present invention is to provide a joint mechanism which is capable of joining structural members angularly movably to each other at a freely selected angle between the joined structural members.